chore: rename course optimizer name in dropdown

Author: Muhammad Faraz Maqsood

cms/templates/widgets/header.html

@@ -264,7 +264,7 @@ <h3 class="title"><span class="label">${_("Tools")}</span> <span class="icon fa
                   </li>
                   % if optimizer_enabled:
                   <li class="nav-item">
-                    <a href="${get_optimizer_url(course_key)}">${_("Optimize Course")}</a>
+                    <a href="${get_optimizer_url(course_key)}">${_("Course Optimizer")}</a>
                   </li>
                   % endif
                 </ul>